A large number of people would be exposed to irradiation in large-scale nuclear and radiation accidents or nuclear terrorist attacks. Therefore, it is urgent to establish rapid and high-throughput biodosimetry for in triage, providing a basis for emergency management. Imaging flow cytometry (IFC) possesses the high through put advantages of traditional flow cytometry and the sensitivity and specificity of microscope, and has a good application prospect in the research and development of rapid, automated, and high-throughput biological dose estimation technology. This article reviews the application progress of IFC in biodosimetry, and provides a reference for the development of biological dose estimation and detection equipment for large-scale nuclear and radiation accidents.

Radiation sterilization is one of the most successful applications of ionizing radiation technologies. This paper reviews research on virus inactivation by ionizing radiation, focusing on its use in virus control for food, blood products, and homologous or heterologous tissue repair materials, inactivated viral vaccine preparation, and high-risk virus-related laboratory sample preparation, and also puts forward some thoughts on the application of ionizing radiation technologies in the prevention and control of coronavirus disease 2019.

Objective To analyze the micronucleus levels of peripheral blood lymphocytes of medical radiation workers, and to provide a basis for radiation protection to reduce occupational hazards caused by ionizing radiation. Methods A total of 1072 medical radiation workers were selected into radiation group, and 329 healthy adults who underwent pre-employment occupational physical examination and intended to be radiation workers were selected into control group. The micronucleated lymphocyte frequency was determined by whole blood micro-culture. Results There were no significant differences in micronucleated cell frequency and micronucleus frequency between the radiation group and the control group (both P > 0.05). The detection rate of micronucleus abnormalities in the radiation group was significantly higher than that in the control group (P < 0.001). Female radiation workers had significantly higher micronucleated cell frequency, micronucleus frequency, and the detection rate of micronucleus abnormalities than male radiation workers (all P < 0.001). Between different types of work, significant differences were observed in micronucleated cell frequency and micronucleus frequency (both P < 0.05), but not in the detection rate of micronucleus abnormalities (P > 0.05). Radiation workers with different lengths of working showed significant differences in micronucleated cell frequency (P < 0.05), micronucleus frequency (P < 0.05), and the detection rate of micronucleus abnormalities (P < 0.001). Significant differences were observed in micronucleated cell frequency and micronucleus frequency between different age groups (both P < 0.05). The Spearman’s rank correlation analysis showed that micronucleated cell frequency and micronucleus frequency were positively correlated with the age of radiation workers (both P < 0.001). Conclusion The micronucleus frequency of radiation workers was related to the type and length of work, and had a positive correlation with age. Radiation protection should be enhanced for workers engaged in medical radiation for a long period, especially female workers and workers with a long length of service.

This paper summarizes and discusses the research and achievements in the effect of irradiation on extending the shelf life and quality guarantee period of seafood, on the quality of seafood, and on seafood sterilization, and seafood irradiation biological dosimeter study, and defines the concepts related to seafood irradiation. Moreover, we propose that irradiation sterilization on severe acute respiratory syndrome coronavirus 2 of cold-chain seafood and seafood irradiation dose control are the main research content and directions.

Health monitoring of radiation workers is an important part of the radiation protection system. Occupational health examination is very important for the safe use of nuclear energy technology. This article analyzes the detection results of radiation-sensitive indicators reported in the literature to investigate the health status of radiation workers and to provide a reference for the further study of sensitive indicators in health monitoring of radiation workers.

OBJECTIVE: To compare the effects of ~(56)Fe~(17+),~(12)C~(6+)ion beams and~(60)Co γ rays on chromosome aberration in human lymphoblastoid cells. METHODS: The human lymphoblastoid cells were divided into 0. 1,0. 3,0. 5,0. 7,1. 0,2. 0 Gy irradiated groups and 0. 0 Gy control group. They were separately exposed to ~(56)Fe~(17+)ion beams( linear energy transfer was 400. 0 ke V/μm),~(12)C~(6+)ion beams( linear energy transfer was 26. 0 ke V/μm) and~(60)C γ rays. Chromosome specimens were harvested 48 hours after irradiation. The effects of different radiation on dicentric plus centric ring( “d + r”) aberration rate and chromosome aberration in human lymphoblastoid cells were detected by light microscope with artificial counting. RESULTS: The “d + r”aberration rates induced by 0. 3-2. 0 Gy ~(12)C~(6+)ion beams were significantly higher than those of ~(56)Fe~(17+)ion beams and~(60)Co γ rays at the same dose( P < 0. 017). Chromosome aberration cell rates of 0. 1-2. 0 Gy ~(12)C~(6+)ion beams were significantly higher than those of ~(56)Fe~(17+)ion beams and~(60)C γ rays at the same dose( P < 0. 017). At the dose range of 0. 0-2. 0 Gy,chromosome aberration effects of three kinds of radiations were gradually increased( P < 0. 01). The relative biological effectiveness of ~(56)Fe~(17+)ion beams was lower than that of ~(12)C~(6+)ion beams.CONCLUSION: The chromosome aberration induced by ~(12)C~(6+)ion beams was more serious than that of~(60)Co γ rays and ~(56)Fe~(17+)ion beams.

Objective To analyze the effect of high and low dose radiation on the expressions of Th1,Th2 and Th3 /Tr1 related-genes in mice thymocytes and investigate the possible underlying molecular mechanism.Methods ICR mice were randomly divided into low-dose group (0.075 Gy),high-dose group (2.0 Gy) and sham-control group.The mouse thymus tissue was extracted at 16 hours after irradiation and the expressions of Th1-Th2-Th3 related genes were measured by PCR array.Results Eight genes were up-regulated and five genes were down-regulated after low dose radiation (0.075 Gy);while 54 genes were up-regulated and three genes were down-regulated after high dose (2.0 Gy) radiation.These genes included Th1 cell related genes,Th2 cell related genes,Th3/Tr1 cell related genes,Th1/Th2 immune response genes and transcription factor related genes.Low dose radiation induced up-regulation of Stat4 and Socs1 of genes related to the Th1 cells,and it induced down-regulation of IL-4ra,Cebpb,Gata3 and Tgfb3 associated with Th2 and Th3 cells,which lead to Sftpd genes up-regulation of Th1 immune response eventually.The high dose radiation up-regulated all of Th1,Th2 and Th3/Tr related genes and also enhanced the expressions of Cd86,IL-18,IL-10 and Irf4 genes related to Th2 immune response,but it did not alter the gene expression of Th1 immune response.Conclusions Low-dose radiation induces Th1-type immune response,while high doses radiation triggers Th2 type immune response.

Objective To explore the effect of miR-9 on the expression of NRP1 and its radiation effects in A549 cells.Methods Bioinformatics was used to analyze the potential binding sites of has-miR-9 and NRP1-3'UTR.The miR-9 sequence was inserted into pcDNA-DEST-47 plasmid to construct the eukaryotic expression vector (pcDNA-DEST-miR-9) and to construct the NRP1 gene 3'UTR luciferase reporter plasmid (pEZX-MT05) at the same time.They were simultaneously transferred into A549 cells for analysis of the regulatory effect of miR-9 on the expression of NRP1.Meanwhile miR-29b was used as a negative control to observe whether or not NRP1 gene was a target of miR-9.After 10 Gy irradiation,the expression of NRP1,and the inhibitory effect of miR-9 on it was confirmed by Western blot assay.The expression of miR-9 was detected by real-time PCR.Results It was found that miR-9 reduced the luciferase activity of NRP1-3'UTR wild plasmid (t =3.906,P ＜ 0.05) but not NRP1-3' UTR mutant plasmid.This luciferase activity was not inhibited by other types of miRNA (miR-29b).The expression of NRP1 protein in A549 cells was decreased after the cells were transfected with miR-9 mimic.After irradiation with dose of 10 Gy,the expression of miR-9 were decreased (t =37.319,P ＜ 0.05) and the expression of NRP1 protein were increased.Conclusions miR-9 regulates the expression of NRP1 by targeting 3'UTR site of NRP1 gene in A549 cells.

Objective To explore the role of PLC/PIP2 signal pathway in the changes of mouse thymus CD4 + CD25 + NRP1 + Treg and TGF-β1 after different doses of X-ray irradiation Methods 36 ICR mice were randomly divided into 6 groups according to the irradiation doses of 0,0.5,1.0,2.0,4.0 and 6.0 Gy,respectively.Flow cytometry was used to detect the expression of NRP1 + Treg,and ELISA was used to detect the expression of TGF-β1 in mouse thymocytes at 16 h post-irradiation.The EL-4 cells were irradiated by X-rays at the dose of 4.0 Gy after co-cultured with the PMA and TMB-8 for 2 hours.Flow cytometry was used to detect the expression of NRP1 + Treg,and ELISA was used to detect the changes of TGF-β1 at 48 h post-irradiation.Results The NRP1 + Treg appeared a transient decrease at both 0.5 and 1.0 Gy irradiation and reached its valley value at 1.0 Gy (t =6.96,P ＜ 0.01),then showed a dosedependent increase and reached its peak at 6.0 Gy (t =6.70,P ＜ 0.01).The TGF-β1 level decreased after 0.5 Gy X-rays (t =12.53,P ＜0.01),then increased at a dose-dependent manner and reached its peak at 4.0 Gy (t =10.40-19.56,P ＜ 0.01).Compared with the sham-irradiation,NRP1 + Treg was decreased significantly after PMA treatment (t =3.06,P ＜ 0.01),while it was up-regulated significantly after irradiation in the presence of PMA (t =8.27,P ＜ 0.01).TGF-β1 was reduced in the presence of PMA with or without irradiation (t =10.46-39.69,P ＜ 0.01).NRP1 + Treg and TGF-β1 were increased significantly after TMB-8 treatment (t =5.53-44.26,P ＜ 0.01).Conclusions NRP1 + Treg cells and TGF-β1 were up-regulated after a high dose radiation,and the PLC/PIP2 signal pathway may participate in the regulation.

Objective To investigate the effects of TLR4 on the radiosensitivity of tumor cells.Methods The cell lines of RAW264.7,Lewis,MFC,Hepal-6,Bl6,and NIH3T3 were irradiated with 5 Gy X-rays or sham-irradiated.24 h after irradiation,the expression of TLR4 was detected by flow cytometry.According to the TKR4 level,cells were divided into three groups:without treatment,LPS stimulation and TAK242 block.CCK-8 kit and Annexin-V Apoptosis Kit were used to detect cell proliferation,apoptosis and cell cycle distribution of each group.Results After 24 h of 5 Gy ionizing radiation,TLR4 was significantly increased in Lewis cells (t =-8.68,P ＜0.01) but decreased in MFC cells (t =25.8,P ＜ 0.01) and had no significant changes in Hepal-6,B16 and RAW264.7 cells.In addition,the proliferation vitality (t =57.62,-6.23,P ＜ 0.01) and survival fraction (t =13.37,19.24,P ＜ 0.01) of the Lewis and MFC cells were reduced especially for the TLR4-blocked cells,and the apoptosis rates of both Lewis (t=-167.85,P＜0.01) and MFC cells (t=-26.45,P＜0.01) were elevated.The percentages of G0/G1 phase and S phase Lewis cells were significant increased (t =8.68,14.89,P ＜ 0.01) but its G2/M phase were reduced (t =-37.48,P ＜ 0.01).However,the percentages of G0/G1 phase and S phase MFC cells were obviously reduced (t =20.31,4.48,P ＜ 0.01) and G2/M phase increased (t =-13.06,P ＜ 0.01).For both cell lines of Lewis and MFC,the cycle distribution of TAK242 and LPS groups didn't change significantly.Conclusions High expression TLR4 in the Lewis cells is related to cell proliferation and apoptosis but not cell cycle distribution,and hence TLR4 could influence the radiosensitivity of tumor cells.